Door alarm



Oct. 6, 1931. z. PEHEL E1' AL 1,825,883

Doon ALARM Filed Dec. 20. 193D Patented Oct. 6, 1931 NETE STATES ZYGIVIUNT PEI-IEL, OF NEW' YORK, N. Y., AND ZYCI-Ir, OF LNDEN, NEW' ERSEY noon ALARM Application filed December 2o', 193e.y serieu No. 503,656.Y

This invention relates to improvements in burglar alarm devices and more particularly to such a device that may readily be attached to a door knob spindle or the like, and it is 5 the principal object of our invention to provide al device by the use of which an alarm will be sounded whenever the knob spindle is rotated in either direc-tion in an ettort to open the door. Another object of our invention is the provision of a burglar alarm device of comparatively simple and inexpensive construction, yet durable and highly elilcient in operation.

A further object of our invention is the 5J provision of a burglar alarm device including a sounding member, sounded by novel and improved clapper members alternately engaging the sounding member upon the turning of the door knobs and their spindle.

still further object of our invention is the Vprovision of a burglar alarm device readily attached to and removed `from a door knob spindle or other similar device, the body of which is equipped with means to limit its swinging motions in either direction. n

V,Further objects and advantages of our device will become more fully known as the description thereof proceeds and will then be specifically detined in the appended claims.

In the accompanying drawings forming a material part of this disclosure:

Fig. 1 is a fragmentary/edge view of a door equipped with an alarm device constructed according to our invention.

ltig. 2 is a front elevation thereof.

Fig. 3 is a front elevation of the alarm device on an enlarged scale.y partly in section.

Fig. l is a sectional end elevation .of the alarm device, Figure 3.

As illustrated, a door l() is equipped with the usual door knobs ll and l2 on'spindle The alarm device comprises a body le having an outer curved member l5 provided with a socket 16 allowing the passage or" a clamp screw 17 formed at its outer end with a thumb piece 18 and at its inner end a curved plate 18 for engagement ofthe door spindle 13 to clamp the device to the same betweenisaid plate and a similarly curved seat 19 of body lll.

The sounding member 20 ot a bell is attached by means of the pin 2l to a plate 22 secured to the doorand the outer threaded endy of. the pin carries the usual nut 23.'

The lower end of body le is segmentally shaped and provioed with teeth 24 in mesh with the teeth of a comparatively large and Wide gear 22.

n. Smaller gears 27, 28, on spindles 29. 30, arev in mesh jwith the 'teeth ol' the large gear 25min opposite sides thereof.

The spindles 29, 30, carry each arms 3l eX- tending in opposite directions from said spindles and having their ends slotted, at 3:2, and in these slots the pins 33 of clapper members '34 are guided.

The body 14 is provided near its lower end withk an arcuatehorizontal slot into which 'extends the pin 2l, and the ends of the slot limit the lateral displacement of body 14.

The operation of our device will be entirely clear from the above description and inspection of the drawings, and it will be evident that the device can be readily attached by means of the clamp to the spindle of the door knobs.

It now the knobs are rotated in an effort to open the door, the toothed segmentZ/l of body le will turn gear 25 in either direction which through the engagement with vthe smaller gears 27, 2S, will turn the same also and their spindles will rotate and operate the clapper members 3e to engage the sounding member 20 and thus give the alarm. f

It will be understood that we have described and'shown the preferred forni of our device only as one example of the many possible ways to practically construct the same, and that we may make such changes 25 on a spindle 26 secured in plate in the general arrangement of our device and in the construction of the minor details there'- of as come within the scope of the appended claims without departure from the spirit of Vour invention.

Having thus described our invention, what" we claim as new and desire to secure by Letters Patentis:

1. An attachment for door knob spindles comprising a body member adapted to be clam d to the spindle having an arcuate slot ormed therein, a toothed segment at the lower end of said body member, a sounding member, a pin for receiving the same to a support passing through the slot in said body member to limit the lateral movements of seid bodyv participating in the turning movements of the door knob spindle, a gear in said sounding member in mesh with the teeth of said segment, smaller gears in mesh with said gear, and clapper elements operated from said smaller gears to alternately engage the sounding element upon the rotation of the door knob spindle 2. In an attachment of the class described, a sounding member, a comparatively large and wide gear therein, means for operating said gear upon the turning of the knob spindle., smaller gears in mesh with said large gear at opposite sides thereof, spindles for said smaller gears, arms on said spindles extending in opposite directions therefrom and having their ends slotted, and clapper members guided and held in the slots of the ends of said arms adapted to alternately engage the sounding member to sound an alarm upon the rotation of said door spindle in either direction, and means for attaching the sounding member to a support.

Signed at New York, in the county of New York, and State of New York, this 19th day of December, A. D. 1930.

ZYGMUNT PEHEL. GEORGE ZYCH. 

